If you were Registered and logged in, you could reply and use other advanced thread options
|
Posted by Tony on October 10, 2009, 1:49 pm
dpb wrote:
> Van Chocstraw wrote:
> ...
>> CC's equate more to Cubic Inches. Foot pounds equate to horsepower.
>
> cc and ci are both displacements, yes.
>
> torque and horsepower aren't the same units at all---
>
>> Multiply horsepower by 33,000 to get foot pounds.
>
> So a 3hp lawnmower has almost 100,000 ft-lb of torque??? Amazing! Them
> are some stout crankshafts...
>
> Actually hp*33,000 --> ft-lbs/minute, _not_ ft-lb (as the table shows).
> The "per minute" part is significant here.
Yes, "per minute" is the key. Same as how horsepower is measured.
"Horsepower is defined as work done over time. The exact definition of
one horsepower is 33,000 lb.ft./minute. Put another way, if you were to
lift 33,000 pounds one foot over a period of one minute, you would have
been working at the rate of one horsepower. In this case, you'd have
expended one horsepower-minute of energy."
http://www.web-cars.com/math/horsepower.html
|
|
Posted by dpb on October 10, 2009, 1:53 pm
Tony wrote:
> dpb wrote:
>> Van Chocstraw wrote:
>> ...
>>> CC's equate more to Cubic Inches. Foot pounds equate to horsepower.
>> cc and ci are both displacements, yes.
>> torque and horsepower aren't the same units at all---
>>> Multiply horsepower by 33,000 to get foot pounds.
>> So a 3hp lawnmower has almost 100,000 ft-lb of torque??? Amazing!
>> Them are some stout crankshafts...
>> Actually hp*33,000 --> ft-lbs/minute, _not_ ft-lb (as the table
>> shows). The "per minute" part is significant here.
>
> Yes, "per minute" is the key. Same as how horsepower is measured.
>
> "Horsepower is defined as work done over time. The exact definition of
> one horsepower is 33,000 lb.ft./minute. ...
Well, DOH! if 1-hp * 33,000 ft-lb/min/hp = 1 hp I guess it would follow
that the definition of 1 hp <==> 33,000 ft-lb/min...
--
|
|
Posted by ransley on October 10, 2009, 3:20 pm
wrote:
> Worn Out Retread wrote:
> > I am looking for a new snow blower and have discovered that the power
> > rating of the engines are no longer in "Horse Power" but in "Foot
> > Pounds" if given at all. Sometimes all that is given is the CC's of the
> > engine.
> > Even the people selling these machines don't know what the "Horse Power=
"
> > ratings are so that old geezers like myself can understand what is goin=
g
> > on. Does anyone have any general rules regarding the conversion of Foot
> > Pounds or CC's to Horse Power?
> They are just trying to pull one over on us by frigging up standard
> ratings in the US.
> CC's equate more to Cubic Inches. Foot pounds equate to horsepower.
> Multiply horsepower by 33,000 to get foot pounds.
> It's just another crooked business tactic to screw you over.
> See the chart:http://www.geocities.com/MotorCity/Show/3753/convert.htm
CC is cubic centimeters, CI is cubic inch, my new toro is 6.75 ft lbs
of crap, it doesnt cut as well as an old 3.5 hp engine, the new
ratings just decieve all. I thought my toro was 6.75 hp, I was ready
to junk it because it bogs so bad.
|
|
Posted by on October 10, 2009, 7:58 pm
On Sat, 10 Oct 2009 12:20:17 -0700 (PDT), ransley
>wrote:
>> Worn Out Retread wrote:
>> > I am looking for a new snow blower and have discovered that the power
>> > rating of the engines are no longer in "Horse Power" but in "Foot
>> > Pounds" if given at all. Sometimes all that is given is the CC's of the
>> > engine.
>> > Even the people selling these machines don't know what the "Horse Power"
>> > ratings are so that old geezers like myself can understand what is going
>> > on. Does anyone have any general rules regarding the conversion of Foot
>> > Pounds or CC's to Horse Power?
>> They are just trying to pull one over on us by frigging up standard
>> ratings in the US.
>> CC's equate more to Cubic Inches. Foot pounds equate to horsepower.
>> Multiply horsepower by 33,000 to get foot pounds.
>> It's just another crooked business tactic to screw you over.
>> See the chart:http://www.geocities.com/MotorCity/Show/3753/convert.htm
>CC is cubic centimeters, CI is cubic inch, my new toro is 6.75 ft lbs
>of crap, it doesnt cut as well as an old 3.5 hp engine, the new
>ratings just decieve all. I thought my toro was 6.75 hp, I was ready
>to junk it because it bogs so bad.
It is the "old" 4.5 HP, but because of speed limits it is really
only 3 hp - assuming 2400 RPM limit.
On a 24" mower, the blade tip travels 75.36 inches (6.28 ft) per
revolution. At 3600 rpm that is 22,608 ft per minute - well in excess
of the mandated 19,000 limit. The limit is reached at just 3025 RPM.
So IF it is a 24" mower, it is a 3.88 HP mower.
|
|
Posted by Steve Barker on October 10, 2009, 8:41 pm
clare@snyder.on.ca wrote:
> On Sat, 10 Oct 2009 12:20:17 -0700 (PDT), ransley
>
>> wrote:
>>> Worn Out Retread wrote:
>>>> I am looking for a new snow blower and have discovered that the power
>>>> rating of the engines are no longer in "Horse Power" but in "Foot
>>>> Pounds" if given at all. Sometimes all that is given is the CC's of the
>>>> engine.
>>>> Even the people selling these machines don't know what the "Horse Power"
>>>> ratings are so that old geezers like myself can understand what is going
>>>> on. Does anyone have any general rules regarding the conversion of Foot
>>>> Pounds or CC's to Horse Power?
>>> They are just trying to pull one over on us by frigging up standard
>>> ratings in the US.
>>> CC's equate more to Cubic Inches. Foot pounds equate to horsepower.
>>> Multiply horsepower by 33,000 to get foot pounds.
>>> It's just another crooked business tactic to screw you over.
>>> See the chart:http://www.geocities.com/MotorCity/Show/3753/convert.htm
>> CC is cubic centimeters, CI is cubic inch, my new toro is 6.75 ft lbs
>> of crap, it doesnt cut as well as an old 3.5 hp engine, the new
>> ratings just decieve all. I thought my toro was 6.75 hp, I was ready
>> to junk it because it bogs so bad.
> It is the "old" 4.5 HP, but because of speed limits it is really
> only 3 hp - assuming 2400 RPM limit.
>
> On a 24" mower, the blade tip travels 75.36 inches (6.28 ft) per
> revolution. At 3600 rpm that is 22,608 ft per minute - well in excess
> of the mandated 19,000 limit. The limit is reached at just 3025 RPM.
> So IF it is a 24" mower, it is a 3.88 HP mower.
I've never heard of two things mentioned here:
#1. a 24" push mower
#2. a 2400 rpm limit
AFAIK, all small engines are governed at 3600 and that's where they operate.
s
|
Page 5 of 13 < 1 2 3 > last >>
| Similar Threads | Posted | | Looking for a good snow blower... | December 5, 2005, 9:56 am |
| Help! - Snow Blower Won't Start! | December 20, 2006, 8:20 pm |
| snow blower repair | February 14, 2007, 8:06 pm |
| snow blower parts | February 15, 2007, 10:27 am |
| i want a new good snow blower | December 31, 2007, 9:07 pm |
| Sears snow blower | January 3, 2008, 3:47 pm |
| snow blower repair | March 1, 2008, 6:49 pm |
| Ariens Snow Blower | January 19, 2009, 7:54 pm |
| Snow Blower Manufacturers | October 25, 2009, 11:15 am |
| Snow blower stored over the summer? | July 10, 2005, 9:27 pm |
|
|
Yahoo! 
Google 
Windows Live 
del.icio.us 
digg 
Netscape 
XML Sitemap
> ...